PIXE and Its Applications

Abstract

When charged particles collide with atoms, atomic inner shell electrons are ionized and characteristic X-rays are produced. This phenomenon is called Particle Induced X-ray Emission: PIXE. In the case of K-shell ionization, the ionization process can be theoretically explained very well and the cross-sections follow a scaling law. Since the production cross-sections of characteristic X-rays in PIXE is very large, PIXE can be applied to trace element analysis and uranium from sodium can be simultaneously detected with sensitivity of ppb. Scanning ion beams, we can obtain a concentration distribution of an element contained in a sample as a picture. Furthermore, when micro beams are used, the distributions of elements inside a cell can be investigated. Moreover, when a metal target is irradiated by micro-beams, a point source of characteristic X-rays is made and the development of micron CT with quasimonochromatic X-rays becomes possible. By this micron CT, we can observe the inside of a small living animal body.